This invention relates to ways of extracting and concentrating cannabinoids and terpenes from plant substrates including hemp, and particularly modifying the characteristics of the solvent to by-pass undesired constituents of plants throughout the extraction process.
Extraction of industrial hemp and cannabis can be done via many methods, using a wide array of FDA approved food grade solvents. The most commonly used solvents are hydrocarbons such as hexane, pentane, butane or propane. Lipid based solvents such as canola oil, soybean oil olive oil, flax seed oil, hemp oil are also commonly used in hemp and cannabis extraction methods. Super critical CO2 is also commonly used in cannabis extraction, but the expensive machinery and the post extraction steps required to purify an SFE extract of undesired plant lipids, makes SFE the least desirable method for any commercial processor.
Several drawbacks of hydrocarbon extraction methods have been recognized. The most prominent of these drawbacks is the volatility of hydrocarbon solvents. The cost associated with retrofitting a laboratory with explosion proof electronics, ventilation fans etc. create enormous start-up costs. Second, pure hydrocarbon solvents such as N-butane or N-hexane are extremely difficult to obtain and therefore are hardly ever used for cannabis extract production. The majority of extracts are created with inferior, low quality butane that contains additives and impurities.
Lipid based extractions are much safer and healthier than hydrocarbons, but separating the cannabinoids or flavonoids from a lipid emulsion requires a thorough understanding of chemistry, as well as expensive distillation devices.
Various states and local governments are now legalizing cannabis for medical and recreational use. This creates an entire market of DIY extractions which are obtained through low quality, impure, hydrocarbons such as butane and propane. These extractions not only pose a threat to the consumer, but to the manufacturers as well. Numerous instances have been recorded where home made laboratories have exploded or caught fire because of the unsafe practices of DIY manufacturers.